CN107043986B - A kind of digital weft detecting method and system - Google Patents

Abstract

The invention discloses a digital weft detection method and system, wherein the method includes: collecting the detection signal sent by the weft detection device of the loom in real time; calculating the signal area of the detection signal collected in the first time period before the weft yarn arrives; The signal area of the detection signal collected in the second time period, the first time period is equal to the duration of the second time period; calculate the absolute value ΔS of the area difference between the signal area of the first time period and the signal area of the second time period ; When the absolute value ΔS is not less than the target threshold, it is determined that the weft yarn arrives normally. By comparing the signal areas of the detection signals collected in the first time period before the arrival of the weft yarn and in the second time period after the arrival of the weft yarn, it can be determined whether the weft yarn arrives normally, and the misjudgment caused by the interference can be effectively avoided, thereby effectively increasing the cost. The adaptability of the digital weft detection system and the accuracy of weft detection are invented.

Description

A digital weft detection method and system

technical field

The invention relates to the communication field, in particular to a digital weft detecting method and system.

Background technique

The textile industry originated in the Neolithic Age 5,000 years ago. After the renewal and development of human wisdom, the textile industry has gradually moved from manual processing to mechanization, automation, intelligence and networking. Under the background of the innovation of the times, people no longer only pursue the simple ugliness and cold protection, and the demand for textile processing has gradually changed from extensive to refined, which also makes the high-efficiency and high-quality processing of the loom system a core competitiveness.

Among them, when the loom system is working, the weft detection is a device used to judge whether the fabric weft is normal or not, which is directly related to the processing efficiency and quality of the loom system. The weft detection is like the eyes of the loom system. Only when the weft yarn arrives, can we weave high-quality fabrics.

At present, the domestic weft detection system mostly uses the analog weft detection system, and the working principle of the analog weft detection system is to detect the detection signal sent by the weft detector of the loom, and perform multi-level signal bandpass on the received detection signal Amplify the processing, and input the obtained waveform signal into the comparator for waveform comparison, and judge whether the weft yarn arrives normally or not by counting the number of times the pulse number crosses the level.

Although the analog weft detection system in the prior art can realize high-speed and efficient processing, the analog weft detection system requires the staff to manually adjust the potentiometer, and due to the vibration of the loom during operation, as well as the oil pollution and flying catkins on the application site of the analog weft detection system , dust and other interference, making the number of times the pulse crosses the level abnormal, easily causing misjudgment of the arrival of the weft yarn, requiring the staff to frequently adjust the potentiometer, which also leads to weak anti-interference ability of the simulated weft detection site, and for different Poor mechanical site adaptability.

For this reason, it is necessary to design a new digital weft detecting system to overcome the above problems.

Contents of the invention

The technical problem to be solved by the present invention is to provide a digital weft detection method and system for the shortcomings of the prior art, which can collect the detection signals sent by the weft detector of the loom in real time, and compare the first time period before the arrival of the weft yarn The signal area of the detection signal collected within and within the second period of time after the arrival of the weft yarn can determine whether the weft yarn arrives normally, which can effectively avoid misjudgment caused by interference, thereby effectively increasing the adaptability of the digital weft detection system for field applications and detection. weft accuracy.

The technical scheme that the present invention solves its problem adopts is:

A first aspect of the present invention provides a digital weft detecting method, comprising:

Real-time acquisition of the detection signal sent by the weft detector of the loom;

Calculate the signal area of the detection signal collected in the first time period before the weft yarn arrives, and the signal area of the detection signal collected in the second time period after the arrival of the weft yarn, the first time period and the second time period equal duration;

calculating the absolute value ΔS of the area difference between the signal area of the first time period and the signal area of the second time period;

When the absolute value ΔS is not less than the target threshold, it is determined that the weft yarn arrives normally;

The signal area is calculated by the following formula:

The Σ is a summation operation, the S is the signal area, the Ci(n) is the sample value obtained by processing the detection signal through the discrete Fourier transform DFT algorithm, the M is the summation precision, and the M is associated with the number of samples in the DFT algorithm, and the K is the signal number of detection signals collected in the first time period or in the second time period;

The target threshold is the sum of the basic signal area ΔS1 and the target signal area difference ΔS2, the basic signal area ΔS1 is a preset area value, and the target signal area difference ΔS2 is the current A weft center before the arrival of the weft yarn The absolute value of the minimum area difference of the detection signal change, where A is a positive integer.

Further, before determining that the weft yarn arrives normally, the method also includes:

Comparing the value of the absolute value ΔS and the target signal area difference ΔS2;

When the value of the absolute value ΔS is smaller than the value of the target signal area difference ΔS2, then update the value of the target signal area difference ΔS2 according to the value of the absolute value ΔS;

When the value of the absolute value ΔS is greater than or equal to the value of the target signal area difference ΔS2, then the value of the target signal area difference ΔS2 is retained.

Further, the updating the value of the target signal area difference ΔS2 to the value of the absolute value ΔS includes:

When the absolute value ΔS is less than a preset safety threshold, then retain the value of the target signal area difference ΔS2;

When the absolute value ΔS is greater than or equal to a preset safety threshold, the value of the target signal area difference ΔS2 is updated to the value of the absolute value ΔS.

The second aspect of the present invention provides a digital weft detecting system, comprising:

The collection module is used to collect the detection signal sent by the weft detector of the loom in real time;

The first calculation module is used to calculate the signal area according to the collected detection signal, the signal area includes the signal area of the detection signal collected in the first time period before the arrival of the weft yarn and in the second time period after the arrival of the weft yarn, the said signal area The duration of the first time period is equal to that of the second time period;

The second calculation module is used to calculate the absolute value ΔS of the area difference between the signal area of the first time period and the signal area of the second time period;

A determining module, configured to determine that the weft yarn arrives normally when the absolute value ΔS is not less than a target threshold;

In the first calculation module, the signal area is calculated according to the following formula:

The Σ is a summation operation, the S is the signal area, the Ci(n) is the sample value obtained by processing the detection signal through the discrete Fourier transform DFT algorithm, the M is the summation precision, and the M is associated with the number of samples in the DFT algorithm, and the K is the signal number of detection signals collected in the first time period or in the second time period;

The target threshold is the sum of the basic signal area ΔS1 and the target signal area difference ΔS2, the basic signal area ΔS1 is a preset area value, and the target signal area difference ΔS2 is the current A weft center before the arrival of the weft yarn The absolute value of the minimum area difference of the detection signal change, where A is a positive integer.

Further, the system also includes:

A comparison module, configured to compare the value of the absolute value ΔS and the target signal area difference ΔS2;

An updating module, configured to update the value of the target signal area difference ΔS2 according to the value of the absolute value ΔS when the value of the absolute value ΔS is smaller than the value of the target signal area difference ΔS2;

The update module is specifically further configured to retain the value of the target signal area difference ΔS2 when the value of the absolute value ΔS is greater than or equal to the value of the target signal area difference ΔS2.

Further, the update module is also specifically used for:

When the absolute value ΔS is less than a preset safety threshold, then retain the value of the target signal area difference ΔS2;

When the absolute value ΔS is greater than or equal to the preset safety threshold, the value of the target signal area difference ΔS2 is updated to the value of the absolute value ΔS.

Compared with the prior art, implementing the embodiment of the present invention has the following beneficial effects:

Real-time collection of the detection signal sent by the weft detector of the loom; calculation of the signal area of the detection signal collected in the first time period before the arrival of the weft yarn, and the signal area of the detection signal collected in the second time period after the arrival of the weft yarn, the first time The duration of the segment is equal to that of the second time segment; the absolute value ΔS of the area difference between the signal area of the first time segment and the signal area of the second time segment is calculated; when the absolute value ΔS is not less than the target threshold, it is determined that the weft yarn arrives normally. By comparing the signal area of the detection signal collected in the first time period before the arrival of the weft yarn and the second time period after the arrival of the weft yarn, it can be determined whether the weft yarn arrives normally, and the misjudgment caused by the interference can be effectively avoided, thus effectively increasing the cost The adaptability of the digital weft detection system and the accuracy of weft detection are invented.

Description of drawings

Fig. 1 is a schematic diagram of the working principle of the digital weft detecting system in an embodiment of the present invention;

Fig. 2 is a schematic diagram of an embodiment of a digital weft detecting method in an embodiment of the present invention;

Fig. 3 is a schematic diagram of an embodiment of the digital weft detecting system in the embodiment of the present invention;

Fig. 4 is a schematic diagram of another embodiment of the digital weft detecting system in the embodiment of the present invention;

Fig. 5 is a schematic diagram of another embodiment of the digital weft detecting method in the embodiment of the present invention.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

In the embodiment of the present invention, the loom weft finder may include a sending end and a receiving end, wherein the sending end may transmit a detection signal, and the receiving end may collect the detection signal sent by the sending end, and the detection signal may be a sinusoidal signal with a frequency f signal (i.e. a sinusoidal carrier). When a weft yarn flies between the sending end and the receiving end of the weft finder, the carrier wave of the detection signal is diffracted, but the carrier frequency of the detection signal collected by the receiving end of the weft finder remains unchanged (that is, detection The period of the signal is constant), but the carrier amplitude of the detection signal fluctuates, and the loom system can determine the arrival status of the weft yarn by using the variation of the carrier amplitude.

As shown in Figure 1, in the digital weft detecting system of the present invention, the receiving end of the weft detecting device of the loom can receive the detecting signal with the carrier frequency f sent by the transmitting end, and utilize the analog signal of the detecting signal fed back by the receiving end , the analog signal of the detection signal can be filtered and amplified by a first-stage band-pass amplifier circuit, and the analog signal of the detection signal can be converted into a digital signal by using AD conversion (Analog-to-DigitalConvert, analog-to-digital conversion), and can be sampled The sampling point in the converted digital signal obtains the sample value, and the sample value can be processed by using the discrete Fourier transform DFT (Discrete FourierTransform) algorithm to obtain the sample value of the sample value, and the detection signal can be calculated by integrating the sample value The signal area of the loom, wherein the loom process angle information can be in the range of 100 degrees to 300 degrees, and the 100 degrees and 300 degrees can refer to the angle at which the main shaft of the loom turns to 100 degrees and the angle at which it turns to 300 degrees, respectively. Moreover, when the loom is running, no weft can be reached when the main shaft of the loom is turned from 100 degrees to 200 degrees, and the signal area of the detection signal in the interval from 100 degrees to 200 degrees is calculated by using the DFT algorithm. When the weft yarn arrives at 300 degrees, the carrier amplitude of the detection signal fluctuates, and the DFT algorithm can be used to calculate the signal area of the detection signal whose amplitude changes in the interval from 200 degrees to 300 degrees.

In the embodiment of the present invention, the digital weft detection system can judge the arrival condition of the weft yarn of the loom by comparing the difference values of the above two groups of signal areas, and can report to the loom system when the main shaft of the loom turns to 300 degrees Arrival angle and status information of weft yarns. It should be noted that two situations may be included in the above-mentioned weft yarn, as shown in Figure 1, the reflective yarn represented by white yarn will cause the carrier amplitude of the detection signal to increase when it passes through the weft detector; The light-absorbing yarn represented by black yarn will cause the carrier amplitude of the detection signal to decrease when it passes through the weft detector.

Specifically, as shown in Figure 2, Figure 2 is an embodiment of the digital weft detection method in the embodiment of the present invention, including:

S201. Collect the detection signal in the first time period before the arrival of the weft yarn, and calculate the signal area in the first time period;

In this step, the digital weft detecting system can collect the detecting signal sent by the transmitting end of the weft detecting device in real time by controlling the receiving end of the weft detecting device, and obtain the digital signal of the detecting signal through AD conversion. And when the loom is running, the main shaft of the loom weaves one weft every one cycle (360 degrees), wherein in the process of the main shaft of the loom running for one week, the weft detector has not detected the arrival of the weft yarn in the first time period, the number The weft detecting system can collect detection signals in the first time period before the arrival of the weft yarn. In this embodiment, it is assumed that the weft detector detects the arrival of the weft yarn when the main shaft of the loom is rotated to 200 degrees. In this embodiment, the main shaft of the loom is The interval from 100 degrees to 200 degrees of rotation is used as the first time period collected by the digital weft detecting system, but it should not be construed as a limitation to this embodiment. Moreover, within the angle of rotation of the main shaft of the loom before the weft detector detects that the weft yarn arrives, the digital weft detecting system can also use an interval other than the interval of 100 degrees to 200 degrees as the first time period of collection, for example: at 50 degrees To 200 degrees, 50 degrees to 150 degrees as the first time period and so on.

The rotation angle of the main shaft of the loom can be uploaded to the digital weft detecting system through the encoder of the main shaft of the loom in real time.

It should be noted that the digital latitude detecting system can start from the detection signal collected when the 100-degree information uploaded by the encoder is received, and end with the detection signal collected when the 200-degree information uploaded by the encoder is received. The detection signal is used as the detection signal collected in the first time period, and the signal area of the detection signal collected in the interval from 100 degrees to 200 degrees (that is, in the first time period) is calculated. Moreover, the digital weft finder can start timing when it receives the 100-degree information uploaded by the encoder, and end timing when it receives the 200-degree information uploaded by the encoder, so as to obtain the duration of the first time period, which will not be done here specifically. limited.

In this step, the detection signal collected by the digital weft detection system in the first time period can be composed of multiple continuous sinusoidal signals, and through AD conversion, there will also be multiple continuous sinusoidal signals in the digital signal converted from the detection signal. A sine-like sinusoidal signal of (calculated as a sinusoidal signal in this embodiment). In an ideal non-interference state, since the carrier frequency f of the detection signal is fixed, the sinusoidal signal in the detection signal can be a sinusoidal signal with the same period and amplitude. However, in practical applications, interferences such as reed vibration, oil stains, dust, and flying catkins in different field applications, because the carrier frequency of the detection signal can be a high frequency, such as 60kHz, the above interference will cause at least An abnormal amplitude of a sinusoidal signal. In this embodiment, using the sampling values sampled in the digital signal converted from the detection signal, the digital weft detection system can calculate the signal area of the sinusoidal signal with normal amplitude and abnormal amplitude in the collected detection signal, and The total signal area of the detection signals collected during the first time period may be obtained by superimposing and accumulating.

Based on this, using the discrete Fourier transform DFT algorithm, the digital weft detection system can collect N sampling points for each sinusoidal signal in the digital signal converted from the detection signal collected in the first time period. The value of N can be an integer multiple of 2 or an integer power of 2, and the N sampling points can be equally spaced sampling, that is, N sampling points are collected at equal intervals within a period of a sinusoidal signal. For example: if N is 2 ⁵ , then N is equal to 32, that is, the digital weft detecting system can collect 32 sampling points at equal intervals within a cycle of a sinusoidal signal.

It should be noted that the above-mentioned sampling is to collect the sampling value of the sampling point, and the sampling value is the value of the sampling point in the digital signal. Transform the DFT to calculate the corresponding sample values, that is, calculate the amplitude in the detection signal; use the calculated amplitude to perform integration and accumulation to calculate the signal area of a single sinusoidal signal in the digital signal, and thus calculate Separate out the signal areas of multiple continuous sinusoidal signals in the digital signal, and perform cumulative calculation to obtain the signal area of the digital signal converted from the detection signal collected in the first time period, that is, the signal area of the detection signal.

And, assuming that the sample value of N sampling points calculated by the discrete Fourier transform DFT is Ci(n), the summation accuracy of the signal area of the single sinusoidal signal calculated by integral accumulation is M (this M is the single sinusoidal In the signal, the sample values of M sampling points are taken to calculate the summation accuracy, and the M can be a positive integer less than or equal to N. In the embodiment of the present invention, M can be preferably taken to be equal to N), and the acquisition in the first time period The signal number of the sinusoidal signal in the digital signal converted by the detected detection signal can be set as K, and the signal area calculation formula for calculating the detection signal in the first time period can be obtained as follows:

In the above calculation formula (1), the Σ represents a summation operation, and the signal area S of the detection signal in the first time period can be calculated by using the double summation method.

Specifically, its calculation process can be as follows:

First, you can use the discrete Fourier transform formula DFT:

Wherein, in the calculation formula (2), X(k) is the sample value corresponding to the N sampling points to be calculated, N is the above N sampling points, and n represents the sampling samples of the above N sampling points (for example: the first 0 sample, the first sample, the N-1th sample, etc.), x(n) is the sampling value of the sampling point corresponding to the above sampling sample, e is the natural base, j is an imaginary number, and k corresponds to the above It is a sampling sample from 0 to N-1. It should be noted that in this embodiment, the signals received by the receiving end of the weft finder are mainly concentrated on the carrier frequency of the detection signal, and k=1 can be preferentially selected to filter out The influence of higher harmonics;

Also, Euler's formula can be used to get

Therefore, it can be concluded

Then, the sample value X(k) (i.e. the amplitude) of the N sampling points in the single sinusoidal signal calculated by the above calculation formula (4) is set as Ci(n), and it can be calculated by integrating and accumulating it. The signal area of a sinusoidal signal can be calculated as follows:

Wherein, in above-mentioned calculation formula (5), can be by calculation formula: (6) deformation gain, its purpose is in order to calculate the effective value of Ci (n); θ in this calculation formula (6) is in the above-mentioned calculation formula (5) That is, the period of a sinusoidal signal is evenly divided into M parts, and the phase angles of M points are determined to obtain the sine value; and, 1/M in the above calculation formula (5) corresponds to the width of the signal area calculated by the integral method, That is, the reciprocal of the sampling period, that is, the sampling interval.

Then, after calculating the signal area of a single sinusoidal signal by using the calculation formula (5), the signal area of the sinusoidal signal in the digital signal converted from the detection signal collected in the first time period is accumulated to obtain the second The signal area of the detection signal within a period of time, the specific calculation formula can be as follows:

Assuming that the number of sinusoidal signals in the converted digital signal of the detection signal collected in the first time period is K, then there are,

It should be noted that the calculation process of the above calculation formulas (1) to (7) may be a preferred solution in the embodiment of the present invention, and shall not be construed as a limitation to the embodiment of the present invention.

S202. Collect the detection signal within the second time period after the arrival of the weft yarn, and calculate the signal area in the second time period;

In this step, in the second time period when the weft detector detects the arrival of the weft yarn, the digital weft detecting system can collect the detection signal in the second time period after the arrival of the weft yarn, and can obtain the corresponding signal of the detection signal through AD conversion. digital signal. In this embodiment, it is assumed that the weft detector detects the arrival of the weft yarn when the main shaft of the loom rotates to 200 degrees. In this embodiment, the interval between 200 degrees and 300 degrees of the main shaft of the loom is used as the second time collected by the digital weft detecting system. Paragraphs, however, should not be construed as limiting this embodiment. And, within the angle of rotation of the main shaft of the loom after the weft detector detects the arrival of the weft yarn, the digital weft detecting system can also use intervals other than 200 degrees to 300 degrees as the second time period for collection, for example: 200 degrees to 300 degrees. 350 degrees, and the interval between 250 degrees and 350 degrees are used as the second time period and so on.

The rotation angle of the main shaft of the loom can be uploaded to the digital weft detecting system through the encoder of the main shaft of the loom in real time.

It should be noted that the digital weft detecting system can start from the detection signal collected when the 200-degree information uploaded by the encoder is received, and end with the detection signal collected when the 300-degree information uploaded by the encoder is received. The detection signal is used as the detection signal collected in the second time period, and the signal area of the detection signal collected in the interval from 200 degrees to 300 degrees (that is, in the second time period) is calculated. Moreover, the digital weft finder can start timing when it receives the 200-degree information uploaded by the encoder, and end the timing when it receives the 300-degree information uploaded by the encoder, so as to obtain the duration of the first time period, which will not be done here specifically. limited.

It should be noted that the duration of the first time period may be equal to the duration of the second time period, and when the first time period is 50 degrees to 200 degrees, the second time period may be 200 degrees to 350 degrees; and When the first time period ranges from 50 degrees to 150 degrees, the second time period may range from 250 degrees to 350 degrees, which is not specifically limited here.

In this step, the detection signal collected by the digital weft detection system in the second time period can also be composed of a plurality of continuous sinusoidal signals, and after AD conversion, the digital signal corresponding to the detection signal can also be composed of a plurality of continuous sinusoidal signals. Sine-like sinusoidal signal composition (calculated as a sinusoidal signal in this embodiment). And because the carrier frequency f of the detection signal is fixed and high-frequency, the digital weft detection system can also calculate the normal amplitude and The signal area of the sinusoidal signal with abnormal amplitude can be superimposed and accumulated to obtain the total signal area of the detection signal collected in the second time period.

It should be noted that the calculation of the signal area of the second time period by the digital weft detecting system can be the same as the step of calculating the signal area of the first time period in step S201, and details are not repeated here.

S203. Calculate the absolute value ΔS of the area difference between the signal area in the first time period and the signal area in the second time period;

In this step, after the digital weft detecting system calculates the signal area of the first time period and the signal area of the second time period, it can calculate the area difference between the signal area of the first time period and the signal area of the second time period The absolute value of ΔS.

It should be noted that the digital weft detecting system can store the calculated absolute value ΔS, and the digital weft detecting system can also compare the absolute value ΔS with the minimum absolute value ΔS historically stored in the system, and save the two Among them, the absolute value ΔS with the smallest value. It can be understood that the digital weft detecting system can store the calculated absolute value ΔS of each weft weaved after the loom is powered on. It can also be understood that the digital weft detecting system can also compare the absolute value ΔS with a preset safety threshold, and if the absolute value ΔS is smaller than the preset safety threshold, the digital weft detecting system can determine that the absolute value ΔS If the absolute value ΔS is greater than or equal to the preset safety threshold, the digital weft detecting system can only store the absolute value ΔS, and it can be the same as the minimum absolute value stored in the system history. Value ΔS for comparison.

S204. When the absolute value ΔS is not less than the target threshold, determine that the weft yarn arrives normally.

In this step, when the absolute value ΔS is not less than the target threshold, the digital weft detecting system can determine that the weft yarn of the current loom arrives normally.

Wherein the target threshold may be the sum of the basic signal area ΔS1 and the target signal area difference ΔS2, the basic signal area ΔS1 may be a preset area value, which may be a basic parameter obtained by the designer during a large number of experiments, and The basic parameters can be manually changed by the staff in the practical application of the digital weft detection system; the target signal area difference ΔS2 can be the absolute value of the minimum area difference of the detection signal change in the previous A weft before the arrival of the current weft yarn, that is, the The minimum value of the absolute value ΔS of the area difference between the signal area of the first time period and the signal area of the second time period calculated historically in the digital weft detecting system, A is a positive integer.

Based on the description in the above step S203, when the value of the absolute value ΔS calculated above is smaller than the value of the current target signal area difference ΔS2, the digital weft detecting system can update the value of the target signal area difference ΔS2 to the value of the absolute value ΔS When the value of the absolute value ΔS is greater than or equal to the value of the current target signal area difference ΔS2, the digital weft detecting system can retain the value of the target signal area difference ΔS2.

Moreover, in practical applications, when the value of the absolute value ΔS is less than the current target signal area difference ΔS2 and less than the preset safety threshold, the digital weft detecting system may not update the value of the target signal area difference ΔS2 to the absolute value ΔS The value of the preset safety threshold can be a safety parameter obtained by the designer during the experiment. In order to ensure the safe and normal operation of the digital weft detecting system, it is necessary to ensure that the safety parameter cannot be greater than the detection signal caused by the smallest weft yarn The area difference of the change, so the safety parameter can take a value smaller than the target signal area difference ΔS2, that is, the safety threshold is less than ΔS2, and it is preset in the digital weft detecting system; while the absolute value ΔS is smaller than the current target When the signal area difference ΔS2 is greater than or equal to the preset safety threshold, the digital weft detecting system can update the value of the target signal area difference ΔS2 to the value of the absolute value ΔS.

And, in this step, if the signal area of the first time period is set as S1, and the signal period of the second time period is S2, then:

S2-S1≥△S1+△S2 (8);

That is, △S≥△S1+△S2 (9);

It should be noted that the above calculation formula (9) is applicable to both reflective yarns and light-absorbing yarns during the operation of the loom. The increase value ΔS of the carrier amplitude of the detection signal caused by the weft weft is greater than the sum of the above-mentioned ΔS1 and ΔS2, and the digital weft detection system can determine that the yarn arrives normally; when the yarn is a light-absorbing yarn, if its The decrease value ΔS of the carrier amplitude of the detection signal caused by passing through the weft finder is greater than the sum of the above-mentioned ΔS1 and ΔS2, and the digital weft detecting system can also determine that the yarn arrives normally.

It should be noted that the digital weft detecting system can also upload the arrival angle of the weft yarn to the loom system, and can upload the arrival status of the weft yarn to the loom system, for example: if the digital weft detecting system determines that the weft yarn When it does not arrive normally, that is, ΔS is less than the sum of ΔS1 and ΔS2, the information can be uploaded to the loom system, so that the loom system stops running and sends out an alarm (stopping alarm), which is not limited here.

It should be understood that, when the above-mentioned digital weft detecting system collects detection signals in the first time period, no weft yarn reaches the weft detector within this period, and the detection signals received by the receiving end of the weft detector except the weft detector In addition to the signal with a carrier frequency of f sent by the transmitter transmitter, it also includes interference signals caused by reed vibration, oil stains, dust, flying catkins, etc., so the signal area of the first time period calculated by the digital weft detection system also includes and, in the second time period when the weft yarn arrives at the weft finder, there is also the above-mentioned interference, and the signal area of the second time period calculated by the digital weft detecting system also includes the area of the interference signal Area, using the difference between the signal area of the second time period and the signal area of the first time period, can effectively avoid the misjudgment of the digital weft detection system caused by interference, making it more accurate to judge whether the weft yarn has arrived, and for different The adaptability on site is higher.

Moreover, through high-speed continuous sampling, the amplitude fluctuations caused by various signals can be captured finely; and by continuously comparing the size of ΔS and ΔS2, recording and updating the self-learning process of ΔS2, it can effectively detect the signal for yarn variety replacement. Weakened for self-learning processing, improve the efficiency of the loom.

As shown in Figure 3, Figure 3 is an embodiment of the digital weft detecting system in the embodiment of the present invention, including:

The collection module 301 is used to collect the detection signal sent by the weft detector of the loom in real time;

The first calculation module 302 is used to calculate the signal area according to the collected detection signal, the signal area includes the signal area of the detection signal collected in the first time period before the arrival of the weft yarn and in the second time period after the arrival of the weft yarn, the first time period is equal to the duration of the second time period;

The second calculation module 303 is used to calculate the absolute value ΔS of the area difference between the signal area of the first time period and the signal area of the second time period;

The determination module 304 is configured to determine that the weft yarn arrives normally when the absolute value ΔS is not less than the target threshold.

Optionally, in some embodiments of the present invention, the first calculation module 302 calculates the signal area according to the target calculation formula (10):

In the target calculation formula (10), ∑ is the summation operation, S is the signal area, Ci(n) is the sample value obtained by processing the detection signal through the discrete Fourier transform DFT algorithm, M is the summation precision, and the M and In the DFT algorithm, the number of samples is related, and K is the signal number of detection signals collected in the first time period or in the second time period.

Optionally, in some embodiments of the present invention, the target threshold may be the sum of the base signal area ΔS1 and the target signal area difference ΔS2, the base signal area ΔS1 may be a preset area value, and the target signal area difference ΔS2 It can be the absolute value of the minimum area difference of the detection signal change in the previous A weft before the arrival of the current weft yarn, and A is a positive integer.

Optionally, in some embodiments of the present invention, as shown in Figure 4, the system may also include:

A comparison module 305, configured to compare the value of the absolute value ΔS and the target signal area difference ΔS2;

An updating module 306, configured to update the value of the target signal area difference ΔS2 according to the value of the absolute value ΔS when the value of the absolute value ΔS is less than the value of the target signal area difference ΔS2;

The update module 306 is further configured to retain the value of the target signal area difference ΔS2 when the value of the absolute value ΔS is greater than or equal to the value of the target signal area difference ΔS2.

Optionally, in some embodiments of the present invention, the update module 306 may also be specifically used for:

If the absolute value ΔS is less than the preset safety threshold, then retain the value of the target signal area difference ΔS2;

When the absolute value ΔS is greater than or equal to the preset safety threshold, the value of the target signal area difference ΔS2 is updated to the value of the absolute value ΔS.

Based on the above-mentioned embodiment shown in FIG. 2 and FIG. 3, in the embodiment shown in FIG. 5, another embodiment of the digital weft detection method in the embodiment of the present invention includes:

S501. Start to execute the digital weft detection method;

S502. Determine whether the angle of the loom is in the range of 100 degrees to 200 degrees, if so, execute step S503, otherwise execute step S504;

S503. Perform high-speed sampling on the detection signal, and execute step S506;

S504. Determine whether the angle of the loom is in the range of 200 degrees to 300 degrees, if so, execute step S505, otherwise execute step S502;

S505. Perform high-speed sampling on the detection signal;

S506. Calculate the area of a single signal by using a discrete Fourier transform algorithm;

S507. Calculate the sum of the signal areas of the two sampling intervals respectively;

S508. Calculate the absolute value ΔS of the area difference between the two intervals;

S509. Record and update the target signal area difference ΔS2 of the minimum area difference in the previous A weft before the arrival of the current weft yarn;

S510, judging whether the absolute value ΔS is not less than (ΔS1+ΔS2), if not, execute step S511, if not, execute step S502 and execute step S511;

S511. Upload the arrival angle of the weft yarn and the arrival status of the weft yarn to the loom system (so that the loom system can execute a parking alarm, etc.).

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, many forms can also be made without departing from the gist of the present invention and the protection scope of the claims, and these all belong to the protection scope of the present invention.

Claims (6)

1. a kind of digital weft detecting method, which is characterized in that include the following steps：

The detectable signal that acquisition loom bobbin feeler is sent out in real time；

Second after the signal area of the detectable signal acquired in first time period before calculating weft yarn reaches and weft yarn arrival The signal area of the detectable signal acquired in period, the first time period are equal with the duration of the second time period；

Calculate the absolute value delta of the difference in areas of the signal area of the first time period and the signal area of the second time period S；

When the absolute value delta S is not less than targets threshold, determine that the weft yarn normally reaches；

The signal area is calculated by following calculating formula：

The ∑ is summation operation, and the S is the signal area, and the Ci (n) is to pass through discrete Fourier transform DFT algorithms The sample value that processing detectable signal obtains, the M are summation precision, and the M is associated with hits in the DFT algorithms, institute It is in the first time period or the signal number of the interior detectable signal acquired of the second time period to state K；

The targets threshold is basis the sum of signal area Δ S1 and echo signal difference in areas Δ S2, the basis signal area Δ S1 is preset area value, and the echo signal difference in areas Δ S2 is detectable signal in the preceding A latitudes before the arrival of presently described weft yarn The minimum area absolute value of the difference of variation, the A are positive integer.

2. digital weft detecting method according to claim 1, which is characterized in that before determining that the weft yarn normally reaches, The method further includes：

Compare the value size of the absolute value delta S and the echo signal difference in areas Δ S2；

When the value of the absolute value delta S is less than the value of the echo signal difference in areas Δ S2, then according to the absolute value delta S's Value updates the value of the echo signal difference in areas Δ S2；

When the value of the absolute value delta S is greater than or equal to the value of the echo signal difference in areas Δ S2, then retain the target The value of signal difference in areas Δ S2.

3. digital weft detecting method according to claim 2, which is characterized in that the update echo signal difference in areas Δ The value of S2 is that the value of the absolute value delta S includes：

When the absolute value delta S is less than preset secure threshold, then retain the value of the echo signal difference in areas Δ S2；

When the absolute value delta S is greater than or equal to preset secure threshold, the value of the echo signal difference in areas Δ S2 is updated For the value of the absolute value delta S.

4. a kind of digital weft detecting system, which is characterized in that including：

Acquisition module, the detectable signal sent out for acquiring loom bobbin feeler in real time；

First computing module, for calculating signal area according to the detectable signal of acquisition, the signal area includes that weft yarn reaches The signal area of the detectable signal acquired in second time period in preceding first time period and after weft yarn arrival, described first Period is equal with the duration of the second time period；

Second computing module, for calculating the signal area of the first time period and the signal area of the second time period The absolute value delta S of difference in areas；

Determining module, for when the absolute value delta S is not less than targets threshold, determining that the weft yarn normally reaches；

First computing module calculates the signal area according to following calculating formula：

The ∑ is summation operation, and the S is the signal area, and the Ci (n) is to pass through discrete Fourier transform DFT algorithms The sample value that processing detectable signal obtains, the M are summation precision, and the M is associated with hits in the DFT algorithms, institute It is in the first time period or the signal number of the interior detectable signal acquired of the second time period to state K；

The targets threshold is basis the sum of signal area Δ S1 and echo signal difference in areas Δ S2, the basis signal area Δ S1 is preset area value, and the echo signal difference in areas Δ S2 is detectable signal in the preceding A latitudes before the arrival of presently described weft yarn The minimum area absolute value of the difference of variation, the A are positive integer.

5. digital weft detecting system according to claim 4, which is characterized in that the system also includes：

Comparison module is used for the value size of the absolute value delta S and the echo signal difference in areas Δ S2；

Update module is used for when the value of the absolute value delta S is less than the value of the echo signal difference in areas Δ S2, then according to institute The value for stating absolute value delta S updates the value of the echo signal difference in areas Δ S2；

The update module is specifically additionally operable to be greater than or equal to the echo signal difference in areas Δ S2 in the value of the absolute value delta S Value when, then retain the value of the echo signal difference in areas Δ S2.

6. digital weft detecting system according to claim 5, which is characterized in that the update module is specifically additionally operable to：

When the absolute value delta S is less than preset secure threshold, then retain the value of the echo signal difference in areas Δ S2；

When the absolute value delta S is greater than or equal to the preset secure threshold, by the value of the echo signal difference in areas Δ S2 It is updated to the value of the absolute value delta S.